The technical aspect of the invention concerns itself with transport platforms which can be hauled by a vehicle. The field of use can encompass roadways, or venues that are ice or snow covered. In the first case wheels are appropriate, in the second, skis or ice blades are used with the aid of an adaptor affixed to the existing tires.
The technical singularity of this principle is that of a platform or floor that is pivotally attached to several shafts allowing for vertical movement either downward into a loading/unloading or upward for a travelling position and vice versa.
This vertical movement is completed without any disturbance of the absolute horizontal position of the floor or platform during the displacement phase. The rotation of the assembly occurs around the shaft of the wheels which are blocked at the bottom with the aid of wedges. The force required to raise the platform is provided by the movement of the hauling vehicle.
The advantage of this trailer having a platform which can be lowered to ground level is the elimination of the need for access ramps or the use of "various machines" (Fork-Lift) to raise the load and place it on the floor of the trailer.
These platform trailers can be used to transport all types of vehicles whether they be recreational (motorcycles, snowmobiles, sea-doos, boats, etc.) or utility vehicles (cars, tractors, lawn mowers, etc.). The platform can be fitted with side rails forming a box which can be used in the transport of bulk cargo or other types of load. The box covered with a roof can be used as a live stock carrier for the transport of animals. The loading is carried out very easily since the difference between the level of the ground and that of the level carrying the load is the thickness of the floor itself.
In the preceding examples the term platform designates a surface or a loading plane permitting the transport of "diverse merchandise". But this platform may also serve as a "machine support" and become part of the "machine" itself. These machines, in their uses, must be carried from one location to another (cranes, generators etc.). As part of their working function, their weight is augmented while they are in use, thereby creating the necessity for a solid base laying on the ground and not on wheels.
It is understood that a number of systems have been developed to eliminate the disadvantage of having a loading surface located near to the shaft level of the trailer. These devices were conceived to be used on the hauling vehicle itself or on the trailer, which in this case, becomes a device that is free of the motorized towing assembly, namely a trailer.
The following patents relate to motorized vehicles having a moveable platform:
U.S. Pat. No. 5,035,462 PA1 U.S. Pat. No. 3,707,238 PA1 PCT Patent PCT/AU96/00255 publication WO 96/34778 PA1 U.S. Pat. No. 4,902,188 PA1 European Patent Application 0683089A PA1 French Patent 9109235 PA1 PCT Patent PCT/AU95/00162 publication WO 95/26280 PA1 U.S. Pat. No. 4,673,328 PA1 U.S. Pat. No. 5,288,197 PA1 Canadian Patent 2,146,185
The following patents relate to trailers having moveable platforms:
All these patents show to more of less sophisticated devices capable of lowering and raising a towing platform or motorized vehicles. Yet all these patents mention various ways to allow for the movement of an articulated, or not, platform. These methods could be systems employing one or several jacks, mostly hydraulic, but they may also be electric or pneumatic. The obvious disadvantage is the complexity and the cost associated with these systems which considerably increase the cost of the whole. Another disadvantage is the need to put in place a maintenance program for said systems and their complexity increases the risk of breakdowns.
Other means are also shown, such as U.S. Pat. No. 4,673,328 and Canadian patent 2,146,185 which mention the use of guidance assemblies and winching systems. Given that these systems could be less expensive that the preceding systems, they also make the total cost high. Breakdowns can occur especially in the case of those concerning jamming problems which can occur in the guided area as in U.S. Pat. No. 4,673,328. There can also be a risk of premature wear to the cable causing it to break depending on the environment in which the systems are used.
To summarize, if all these devices allow for easy loading of diverse merchandise while having a mobile vertical platform which remains horizontal at all times or having a vertical non horizontal movement at all times, they are more or less difficult to achieve and therefore expensive.
The solution to all these problems is addressed by the present invention. This consists of a platform furnished with an aft cradle and two fore arms pivotally attached to external longitudinal beams of said platform. The aft cradle constitutes a solid transverse shaft with two vertical arms. The aft cradle arms each supporting at least one spindle with an axle and its wheel. A ski or skate can be fixed to said wheel with the aid of an adjustable strap embracing the circumference of the tire of the wheel. The top of each arm has a joint which allows for the linking of said arms, two by two, in a longitudinal manner. Their joining is achieved by an articulated fork composed of two tie beams linked together by a T-shaped tow bar. This tow bar can be fitted with a device allowing for height adjustment of the hitching point of the head of the assembly which hooks itself to the towing bracket of the hauling vehicle.
The platform rests on the ground, the wheels or skis are immobilized with the aid of wedges, the tow bar and its hitch device are attached to the towing bracket of the vehicle. The vehicle, as it moves forward, allows for the raising of the platform; in effect the assembly pivots around the shaft of the wheels which are immobilised. The fore arms keep the platform horizontal during the vertical movement. When the platform reaches its final upper position the hauling vehicle is immobilised; one can then, with the help of various methods, secure the two tie beams on their respective fore arms. As the trailer is then in a travelling position, we can now remove the wedges.
The advantage of the present invention over other used systems cited in previous patents lies in the use of the hauling vehicle motor towing force which allows for the raising of the platform. This advantage eliminates the use of an external system to produce this towing force as well as reducing the complexity of the operation. This articulated platform is easy to achieve and its use is simple and rapid, which is also an advantage not to be overlooked.
When the platform rests on the ground, the wheel is slightly above ground level, thus permitting the replacement of a flat tire without the use of jacks. It is also possible to slide the skate between the wheel and the ground and to strap it around the tire.
The following description and drawings represent examples of usage but are in no way limited as such. Different types of platforms can be used; we can also use individual muscular force applied against the end of the tow bar to raise the platform. These are different embodiments described in the following examples.